137691731 has 4 divisors (see below), whose sum is σ = 143678352. Its totient is φ = 131705112.

The previous prime is 137691703. The next prime is 137691733. The reversal of 137691731 is 137196731.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 137691731 - 2²⁶ = 70582867 is a prime.

It is a super-2 number, since 2×137691731² = 37918025571552722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137691733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2993276 + ... + 2993321.

It is an arithmetic number, because the mean of its divisors is an integer number (35919588).

Almost surely, 2^137691731 is an apocalyptic number.

137691731 is a deficient number, since it is larger than the sum of its proper divisors (5986621).

137691731 is an equidigital number, since it uses as much as digits as its factorization.

137691731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5986620.

The product of its digits is 23814, while the sum is 38.

The square root of 137691731 is about 11734.2119888811. The cubic root of 137691731 is about 516.3798494570.

The spelling of 137691731 in words is "one hundred thirty-seven million, six hundred ninety-one thousand, seven hundred thirty-one".